Study Finds Social Isolation Could Lead to Cognitive Decline

Social isolation and cognitive decline, including the development of Alzheimer’s disease, could be closely intertwined, according to new research from the University of St. Andrews and Emory University’s Rollins School of Public Health.

The study, published in The Journals of Gerontology, Series B: Psychological Sciences and Social Sciences, found evidence that social isolation may lead to faster cognitive decline, whether or not people felt lonely.  

“Engaging with others, whether they are close to us or strangers, is stimulating and gives opportunities to practice our cognitive skills,” says Solveig Cunningham, PhD, professor of global health at Rollins and senior author of the study.

The Difference Between Isolation and Loneliness 

Social isolation is the distance between one person and others whereas loneliness is a subjective report of feelings of loneliness. While social isolation and loneliness are often thought of as associated, they have independent effects on cognitive function.  

There is a great deal of interest in the health effects of social isolation and loneliness, especially for adolescents and older adults. About a quarter of people 65 and older are identified as socially isolated; likewise, loneliness has been recognized as a major public health issue in high-income countries including the U.S., UK, Sweden, Australia, Germany, and Japan.

Building Community Could Be Protective Against Cognitive Decline 

The researchers analyzed data from the U.S. Health and Retirement study, analyzing 137,653 cognitive function tests taken between 2004 and 2018 for over 30,000 individuals. They found that reducing social isolation can have a protective effect on cognitive function; possible benefits of reducing social isolation were plausible for people across gender, race, ethnicity and educational level.

Lead author of the paper, Jo Hale, PhD, from the University of St. Andrews, said, "Around the holidays, many of us think a lot about how important it is to be surrounded by family and friends. From Pagan winter holidays to classic Christmas tales, we’re reminded that social engagement is good for our mental health. This research shows that it’s also important for our cognitive health. As Alzheimer’s is a leading cause of death for older adults, constructing the scaffolding to allow for regular social interaction, especially for those who mayn’t have family or friends nearby, should be a public health priority.”